Steps

1. The easier half of weighing the costs of cheating on your spouse is to weigh the pros. There is only one: you get to have sex with someone other than your spouse. Because this is the only factor on the positive side, think it over carefully.
2. Consider the following: What is your desire for wanting to cheat? Why not talk to your lover about the problems that you have, and tell him or her what you need in the relationship?
3. If you're unhappy, let your spouse know. It's better to be open than to explain later why you couldn't restrain yourself from fooling around in the first place.
4. When your partner catches on [and he or she will], don't lie. Tell them what you have done. Nobody deserves to be in a relationship where they are not respected.
5. Think about how this news could devastate your spouse. Think about everything that it could ruin.
6. Ask yourself some simple questions: "Am I ready give up my spouse/boyfriend/girlfriend?" "Is one night really worth losing everything that I have and worked hard for?" "How will (spouse's name) feel about this, or feel about me?" "I only have one chance to make this relationship work, am I really planning on wasting it all on one night that will probably lead to nothing anyway?"
7. By asking yourself these questions, and answering them truthfully, you may be surprised as to what you come up with.
8. Ask yourself, how would you, yourself, feel, if your spouse would cheat instead? Nobody has the right for double standards.

Tips

• Think about your spouse's facial expression when you break the news that you've been unfaithful.
• Be an adult about the situation. If you know you're going to cheat, have the decency to break off the relationship first.
• Why drag this relationship on any further? If you're willing to cheat on your spouse, let them out of this relationship. They're already going to be hurt enough when they find out, so don't bring him or her any more pain. Your spouse needs to move on with his or her life, instead of wasting it on an un-truthful and unfaithful person.
• If you have children, think about the type of person you are showing your child to someday become. Be a good parent and role model. Don't hurt your children that way.
• Cheating doesn't just hurt your spouse, it also affects your children, parents, and the rest of your family.
• To learn the science behind why people have unconscious impulses to cheat on and to deceive their spouses, read Sperm Wars.
• If you have decided that you don't want to cheat, tell the intended second partner this directly and avoid getting into any compromising situations with this person (i.e. being alone together, drinking with this person, etc.)
• Consider that you may be a person who does not want a monogamous life. If so, investigate what it takes to live ethically while being free to have multiple partners at the same time. (Look up "nonmonogamy" or "polyamory" on the internet.) Find other people who are like yourself so that you don't hurt your partner(s) by lying or deception.

Warnings

• Once everyone finds out about your cheating ways, you'll find that there are very few people on your side. Nobody will be able to trust you. They will always think of you as a cheater, and a liar.
• If you have something good, don't screw it up on something that can change your entire life for the worse.
• If you are unhappy in your relationship do not stay in it for fear of the breaking up process. Man up, break up, move on. You hurt yourself just as much as others if you stay in an unhappy cheating relationship.